Scaffold



Aug. 29, 1939. e. A. WORTELMANN SCAFFOLD Filed Jan. 14, 1938 2Sheets-Sheet l J20e727'07' @516 v4.

g- G. A. WORTELMA-NN S CAFFOLD Filed Jan. 14, 1938 2 Sheets-Sheet 2Patented Aug. 29, 1939 UNITED STATES- i TENT OFFICE 6 Claims.

The present invention relates generally to scaffolds. More particularlythe invention relates to that type of scaffold which is adapted for useby workmen in connection with work on ceilings and walls and comprises apair of upstanding ladders and a platform forming board between theladders.

One object of the invention is to prpovide a scafiold of this type whichis of new and improved construction and is so designed that it not onlyeffectively and efficiently fulfills its intended purpose but also maybe manufactured at a low and reasonable cost.

Another object of the invention is to provide a scaffold of the typeunder consideration which includes pairs of crossed braces which arelocated at the sides of the ladders and extend between and are connectedat the ends thereof to the side pieces of the ladders.

A further object of the invention is to provide a scaffold of the lastmentioned character in which the ends of the crossed braces areconnected by bolt and slot connections to the side pieces of the laddersand are pivotally connected together at the points where they cross oneanother in order that upon loosening of the bolts the two ladders may bebrought together into a collapsed position for purposes oftransportation or storing.

A still further object of the invention is to provide a scaffold of thetype and character under consideration in which the upper ends of theside pieces of the ladders are shaped to form handles for assisting theusers of the scaffold in mounting or climbing onto the platform formingboard.

Other objects of the invention and the various advantages andcharacteristics of the present scaffold will be apparent from aconsideration of the following detailed description.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by claims at theconclusion hereof.

In the drawings which accompany and form a part of this specification ordisclosure and in which like numerals of reference denote correspondingparts throughout the several views:

Figure 1 is a perspective of a scaffold embodying the invention;

Figure 2 is a plan view;

Figure 3 is a perspective view showing the scaffold in its contracted orcollapsed position;

Figure 4 is any enlarged sectional view taken on the line 4-4 of Figure1 and illustrating the construction and design of the bolt and slotconnections between the ends of the outer braces and the side pieces ofthe ladders;

Figure 5 is an enlarged sectional View taken on the line 5-5 of Figure 1and showing the con- 5' struction and design of the bolt and slotconnections between the ends of the inner braces and the side pieces ofthe ladders; and

Figure 6 is a perspective of one of the flange equipped plates which aremounted on the bolts 10 of the bolt and slot connections and serve toreinforce the slotted ends of the braces.

The scaffold which is shown in the drawings constitutes the preferredembodiment of the ini vention. It is adapted primarily for use insupporting workmen in an elevated position in connection with work onceilings and walls and comprises as the main or essential parts thereofa pair of upstanding ladders 6, a platform forming board I, and twopairs of crossed braces 8.

The ladders ES are positioned one opposite to the other and serve tosupport the board 1 in a horizontal position. They are cross-connectedand suitably strutted by the braces 8 and consist of elongated laterallyspaced side pieces 9 and 5 rungs [0 between the side pieces. The sidepieces are all equal in height and are held in laterally spaced relationby the rungs l0. Preferably the side pieces of each ladder are upwardlyconvergent to a small extent so that the scaffold 30 when in itsoperative or working position is stable and not likely to rock in asidewise manner. Each of the ladders is preferably provided with fourrungs Ill and the latter are round, as shown in the drawings, and havethe ends thereof suitably secured in cylindrical sockets I l in the sidepieces 9. The upper and lower ends of the side pieces 9 project aboveand below the upper and lowermost rungs respectively. The upper ends ofthe ladder side pieces are so cut or shaped that they are tapered orpointed and form upstanding handles l2 above the board 1. These handlesmay be grasped by the users of the scaffold in connection with mountingthe board 1 from the v ladders and serve to hold the board againstsidewise displacement when it is mounted on and supported by theuppermost rungs ID. The rungs are equidistantly spaced and not onlyserve as supporting means for the board but also provide a steparrangement by which the users of the scaffold may climb to or mount theboard.

The board I is adapted to rest on any of the horizontally aligned pairsof ladder rungs I0. It forms or constitutes the platform of the scaffoldand. may be arranged at whatever level or elevation is desired merely byadjusting its position with respect to the rungs. When. the board is inits operative position with the ends thereof resting on a pair ofhorizontally aligned rungs it is held against lateral displacement withrespect to the ladders by the side pieces 9. The length of the board ispreferably slightly greater than the distance between the lowermostrungs of the ladders when the ladders are in their full operative orextended position.

The braces 8 serve to hold the ladders in their operative position andare formed of wood or like light material. At the points of crossing thebraces are pivotally connected together by way of a pair of bolts i3.These bolts are fixed to and project outwardly from the inner braces andproject through holes (not shown) in the adjacent or contiguous portionsof the outer braces. The outer ends of the bolts are provided with wingnuts M which bear against washers 15 on the outer ends of the bolts andoperate when tightened to clamp the inner and outer braces together andhold them against relative pivotal movement with respect to the bolts.The ends of the braces are connected to the ends of the side pieces 9 ofthe ladders 6 by way of bolts l6. These bolts are carried by and projectoutwardly from said side pieces 6 and have threaded outer ends l! onwhich wing nuts I S are mounted. The inner ends of the bolts areprovided with polygonal enlargements l9 and enlarged dome-like heads 20.The enlargements i9 fit within correspondingly shaped polygonal sockets2i in the side pieces of the ladders and serve to hold the bolts againstrotation. The heads 29 abut against the inner side faces of the ladderside pieces and prevent outward movement of the bolts with respect tosuch side pieces. The central portions of the bolts project throughlongitudinally extending slots 22 in the ends of the braces and carryU-shaped plates 23. The slots 22 project outwardly from the centralportions of the braces and terminate inwardly of the end extremities ofthe braces. They are slightly greater in width than the bolts are indiameter and when the nuts it are loosened permit the ladders 6 to beshifted bodily inwards into a. collapsed position wherein they abutagainst one another, as shown in Figure 3. The plates 23 are in the formof metal stampings and have inturned top and bottom flanges 24. They fitagainst the outer side faces of the braces 8 and provide bearings forthe nuts 18. When the latter are tightened the plates 23 are urgedinwards and servein conjunction with the nuts to hold the braces infixed relation with the bolts H5.

The central portion of the plates embody holes 25 for the bolts I6.These holes are substantially the same in diameter as the belts with theresult that the plates are limited to pivotal movement with respect tothe bolts and cannot move laterally or radially with respect to thebolts. The top and bottom flanges 2 3 fit against the top and bottomfaces of the braces respectively and serve to prevent outwardspreading'of the portions of the braces at the sides of the slots 22.When the wing nuts i8 are loosened and the ladders are shifted togetherinto their collapsed or inoperative position, the ends of the bracesride or slide within the flanges of the plates 23. The holes 25 are soarranged that the bolts it are spaced from the sides of the slots 22 andhence there is no likelihood of any wedging or jamming action beingencountered in connection with collapse of the ladders. The threads onthe outer ends of the bolts preferably terminate adjacent to the plates23 in order that they do not damage in any way the sides of the slots 22in the event that such sides are brought into engagement with the bolts.The inner ends of the slots 22 terminate at such distance from the boltsl3 that the ladders are free to be shifted together, as shown in. Figure3. When the ladders are in their collapsed position the lower ends ofthe braces 8 form a stand for supporting the ladders in. an uprightposition. The inner braces are spaced from the outer side faces of theladder side pieces 9 by way of washers 26 and the outer braces arespaced from said side pieces by way of wooden collars 21. The latter aresecured in. place by means of nails 28, as shown in Figure 4, and areequal in thickness to the combined thickness of the washers 26 and theends of the inner braces.

When the scaffold is in its collapsed position and it is desired toplace it in condition for use, the operator or user loosens the wingnuts M at the sides of the ladders and then spreads the ladders apartuntil the bolts it are brought substantially to the outer ends of theslots 22. During outward shift of the ladders B the braces 8 rotateabout the bolts l3 and swing from their ladder supporting position intothe position shown in Figure 1. After separation of the two ladders thewing nuts i l and l8 are tightened. Upon tightening of these nuts thebraces 8 become clamped together and in fixed relation with the ends ofthe side pieces 9 of the ladders and serve fixedly and rigidly to holdthe ladders in their spaced position. After spreading of the ladders andtightening of the nuts the platform forming board I is applied to anydesired horizontal pair of rungs It so that it extends horizontally andfulfills its intended purpose. When it is desired to mount the scaffoldthe user may use either of the two ladders. When it is desired to storeor transport the scaffold, it is only necessary to remove the board "Iand then after loosening the nuts 94 and I8 shift the two ladderstogether, as hereinbefore described. Upon shift of the ladders togetherthe nuts [4 are tightened so as to clamp the braces together and holdthe ladders in place.

The herein described scaffold consists of but a comparatively smallnumber of parts and may be manufactured at a low and reasonable cost.When formed of wood it is comparatively light and may be readilytransported from one place to another when in its collapsed position.

The invention is not to be understood as restricted to the details setforth since these may be modified within the scope of the appendedclaims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. A collapsible scaffold comprising in combination pair of opposedladders adapted when the scaffold is in. its operative position to standsubstantially vertically and in spaced relation, 2. platform formingboard adapted to extend horizontally between the ladders and to have theendsthereof rest on the rungs of the ladders, a pair of crossed bracesextending between the ends of certain of the side pieces of the laddersand having a pivot for the crossed central portions thereof, connectionsin the form of nut equipped bolts on the ends of said certain sidepieces of theladders and longitudinal bolt receiving slots in the endsof the braces, adapted normally to releasable clamping means applied tothe pivot and operative to clamp together in fixed relation said centralportions of the braces and hold them in place when the ladders are intheir operative or inoperative position.

2. A collapsible scaffold comprising in combiation a pair of opposedladders adapted when the scaffold is in its operative position to standsubstantially vertically and in spaced relation, a platform formingboard adapted to extend horizontally between the ladders and to have theends thereof rest on the rungs of the ladders, a pair of crossed bracesextending between the ends of certain of the side pieces of the laddersand having a pivot bolt extending through the crossed central portionsthereof, connections in the form of nut equipped bolts on the ends ofsaid certain side pieces of the ladders and longitudinal bolt receivingslots in the ends of the braces, adapted normally to connect the bracesto the ladders so that the former hold the latter in their operativeposition and upon loosening of the nuts to permit the ladders and bracesto be shifted together into an inoperative or collapsed position, and awing nut on the pivot bolt operative to clamp together in fixed relationsaid central portions of the braces and hold the braces in place whenthe ladders are in their operative or inoperative position.

3. A collapsible scaffold comprising in combination a pair of opposedsimilarly formed rung equipped ladders adapted when the scaffold is inits operative position to stand substantially vertically and in spacedrelation, a platform forming board adapted to extend horizontallybetween the ladders and to have the ends thereof rest on any twoopposedrungs of the ladders, pairs of crossed braces at the sides of theladders extending between the ends of the side pieces of the ladders andhaving the crossed central portions thereof pivotally connectedtogether, and connections in the form of nut equipped bolts on the endsof said side pieces and longitudinal bolt receiving slots in each of theends of the braces, adapted normally to connect the braces to theladders so that the former hold the latter in their operative positionand upon loosening of the nuts to permit the ladders and braces to beshifted together into an inoperative or collapsed position.

4. A collapsible scaffold comprising in combination a pair of opposedladders adapted when the scaffold is in its operative position to standsubstantially vertically and in spaced relation, a platform formingboard adapted to extend horizontally between the ladders and to have theends thereof rest on. the rungs of the latter, a pair of crossed bracesextending between the ends of certain of the side pieces of the laddersand having the crossed central portions thereof pivotally connectedtogether, connections in the form of nut equipped bolts on: the ends ofsaid certain side pieces of the ladders and longitudinal bolt receivingslots in the ends of the braces, adapted normally to connect the bracesto the ladders so that the former hold the latter in their operativeposition and upon loosening of the nuts to permit the ladders and bracesto be shifted together into an inoperative or collapsed position, andplates on the bolts provided with right angle flanges engaging slidablythe portions of the braces at the sides of the slots and serving toprevent outward displacement of said portions.

5. A collapsible scaffold comprising in combination a pair of opposedladders adapted when the scaffold is in its operative position to standsubstantially vertically and in spaced relation, a platform formingboard adapted to extend horizontally between the ladders and to have theends thereof rest on the rungs of the latter, a pair of crossed bracesextending between the ends of certain of the side pieces of the laddersand having the crossed central portions thereof pivotally connectedtogether, connections in the form of nut equipped bolts on the ends ofsaid certain side pieces of the ladders and longitudinal bolt receivingslots in the ends of the braces, adapted normally to connect the bracesto the ladders so that the former hold the latter in their operativeposition and upon loosening of the nuts to permit the ladders and bracesto be shifted together into an inoperative or collapsed position, andmetallic plates mounted on the bolts between the nuts and the braces andhaving inturned flanges engaging slidably the portions of the braces atthe sides of the slots and serving to prevent outward displacement ofsuch portions.

6. A collapsible scaffold comprising in combination a pair of opposedladders adapted when the scaffold is in its operative position to standsubstantially vertically and in spaced relation and consisting of avertical series of rungs and elongated side pieces connected to the endsof the rungs and having the upper ends thereof projecting above theuppermost rungs and shaped to form handles, a platform forming boardadapted to extend horizontally between the ladders and to have the endsthereof rest on the uppermost rungs and fit between the handles, pairsof crossed braces at the sides of the ladders extending between the endsof the side pieces of the ladders and having the crossed centralportions thereof pivotally connected together, and connections in theform of nut equipped bolts on the ends of said side pieces andlongitudinal bolt receiving slots on the ends of the braces, adaptednormally to connect the braces to the ladders so that the former holdthe latter in their operative position and upon loosening of the nuts topermit the ladders and braces to be shifted together into an inoperativeor collapsed position.

GUSTAVE A. WORTELMANN.

